Engine for rock-drills.



G. H. GILMAN. EHGINB Fon Rumi DRILL's.

Ayrimumn mmv JAN. a, 1911.

Patented June 3, 1913.

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Witnesses QV/2M To'czZZ 107mm it may conf-ern:

Beit known that' I, GEORGE H. GILNAN,

a citizen of the United States, and a resident' of Claremont, county ofSullivan, Stateof New Hampshire, (whose'post-ofiice address isClaremont, New; Hampshire,) have in vented an Improvement in Engines forRock-Drills or the Like, ot which the f'ollowing description, inconnection with the accompanying drawings, is a specification, likeletters on the drawings representing like parts. A

This'invention relates to engines andmore particularly, though notexclusively, to engines ofthe direct-acting type such as are used inconnection withrockdrills and other stone working machines.

My invention will be best understood by.

reference to the following description when taken in connection with theaccompanying illustration of one specific embodiment thereof, while itsscope will be more partieularly .pointed out' in the appended claims.

In the drawings: Figure" 1 is a sectional elevation taken through thecylinder and Valve chamber of a rock drill embodying fone form of myinvention; and Fig. 2 is a transverse sectional elevation on the line2-2 in Fig. 1.

Referring to the drawings and more particularly to Fig'. 1, I have thereshown-for the purpose of illustrating the principal teatures of theinvention, the 'piston 1' a-nd y cylinder 2"ot` a rock drill. The pistonrod 3, which projects through 'the forward cylinder head 4 and the feedscrew 5 are shown broken away, but these' parte, as well as thecutting-tool to which the forward end of the piston rod is attached andthe tool hold- 40' ing chuck, may be ol any suitable or well knownconstruction and do not materially concern the herein-describedinvention.

Referring more particularly to the controlling valve 6 the latter is ofthe pressurevractuated piston type having a central head `for vspool '7`which alternately connects the supplyj chamber 8."jwith. the por d O,{"thle former leading* to. thereai 40I' ltad end" `l`ofthe A`-`Cylinderimmediately in ,front o t the "-5O'Sre`a'i head 'or butter11,fandftlielatter` tofthe 4 forwarder tool end of the ,cylinder immedifatelyfbehind'tl'ie front cylinder-head 4.' The 'l engine may be usedwith steam, air, 4or other v pressure fluid. In the' position of thevalve speiaeatin of Letters ratent. Application filed-January 3, 1911.

' groove 19 communicateswith .by means ot' longitudinal v01 valve isthrown to one pfor Vexample the posit' over,the pressureoftheisu'ij y,the smaller end head'u'ntil the pressure li'uid end'zof the valve.

Y chloeefii H. GILMAN, or cLAREMoN'r, NEW HAMPSHIRE, AssrGNoRaso-SULLIVAN MACHINERY COMPANY, or CLAREMONT, NEW HAMPSHIRE, CORPORATIONor MAINE. Y f

ENGINE FOR ROCK-DRILLS.

Patente d une 3.

vseriaiNo.600,403.

shown, the pressure tluid 4passes'from.fthe 55 supply chamber 8 thro' ghthe port; 9: t'o Athe head end of the cylinder, "acting to drive theVpiston forward, the pt )rt` 1() being. at` the same time connectedabout the contracted' or stemk portion of the valve, with vone end ofthe exhaust space 12; When the "valve is lreversed,tl ie port 10 is'connectedvwiththe supply chamber 8 andthe head V:end lport 9 with thepposite end ofthe exhaust space" 12. To reverse the valvethelatter'sj'pro- 65 vided at opposite endswith thesp'ools.l 13 and 14which work in end'chambers'to which pressure is alternatelyfadmitted bythe in ovement of the piston to throwthe valveffThe "chamberfcontainingthe head connected lby a passage 15 (see dottedlines) leading to thegroove 16 in the Walls ofthe cylinder, andthe chamber containingthe'jhead`-14 is connected by means of the passage 1'( (seel dottedlines) withthe` groove 18 in thecylin- 75 der walls. These groovesarealternately uncovered by the reciprocatory movement o the piston, theuncovering of a- 'groove serv-ing to 'admit pressure to that;lendfolt''the' Valve chamber with which thesaid groove 8D is connected,such admission of pressure fluid reversing the position fofY thevalvenfIhe Huid pressure is exhaustedfrom' 'that end "of the valvechamber opposite thel end' td" which pressure is .admittedbymeansof acircumferential groove k19 in the wallsizof the cylinder midway thelength tlf'ie'redt", 'such groove (see Fig. l)y having eonnectionfuiththe external atmosphere through thefexhaust pipe oropening 20." Thecircumferential 90 groove or Vre- @fllt-@e Pi-Sinon .5. Y 29 so that.one end or the'fothen f 'ithe chamber is kept free froif'ifjires'sureflui ing substantially the vfull stroke'otftt ducedportion 21 in thewwall ton. The spool 7 is j otfgreater d1. ieter thanthe lspools 13 and 151 it is t main met o thesupply iurd 'against'ftl isadmitted: as'rlesciibed. a, "ain;irt ,the eppo y This particulai" forniof valve' `and the' arrangement of controlling passagesmay be variedwithin wide lilflitsmf,

or other forms'of l'valves may be substituted 'withoutdeparting from thespirit of my in'- vention hereinafter more fully described.

In theoperationofarrock drill or the like it is' frequently4Ijetp'ii'red to work the piston 11g-and down inthe cylinder withoutdoing e ective work-and wit-hout' permitting the 'iston ltos'trihefeither the upper or the lower ed, v'thisbe1ng necessary, roi"example, *to n Y t as follows: `When the piston moves back on clear outVthe hole or impartA proper-alinement to`-thedr1lL,-steel `in thecase ota deflected-hole. .The up Vor back stroke'- may be f readilyfcontrolledon account of the Weighta'nd inertia of the 'tool o'r tools, but for theu. cushioning ofthe working] stroke. none of l*fflfhas been thoroughlysatisfactory. @inthe illustrated form of tool AI- have provided acushioning valve-24 located transversely the fool end port and adaptedto prevent the escape-:of: fluid pressure from the forwardA end ofthe'cylinder, thereby to cushion the' forward orvdow'nward lstrokeotthetool,

such valve, however, being so constructedl that the' pressurerequired'to produce the necessa y cushion is' automatically 'built upand maintained. '-Referring to' Figs..il and 2, thdvalve 24 ismountediina chamber ransv'ersely the cylinder walls 'and is pro-I vided with theexteriorhan'dle 25 by means of which vit maybe set in the position shownin Fig. I against the stop 2.6 or turned to a position approximately'ninety degrees therefrom a ainst the stop 27. The 'valve isintersectedy the transverse passage 2S and 'is 'also provided with 'thepassage 29 at right angles thereto. Fig.v 1,- pressure-fluid passesfreely throu h the transverse assage-28 to and from' tilde stroke of thepiston, the valve isturned to its opposite position, bringing thepassage 29 into-registration with that portion 'of the port .10'l'eading`to' the valve chamber and 'cutting olf the opposite portion ol the portand the .forwardend of the cylinder from direct co unication with.the-valve char'nloer.` this ition of the-valve lthe vpressure fluid 4cao escape from the forward end` of passage (see Fig. 2) communicatingwith I the passage 29 and opening at the end thereof y. opposite thehandle -25 whereat it forms a assent fora check valve 30. The latteristhe many cushioning devicesA utilized therev A.the'full -area thereof,while at thebottom of In the position shown 1nforward end o thecylinder.- When, howaver, 1t' is desired to cushion the forward-'guidedupon the reduced .end of the threaded plug 31, employed to closethe .end ofthe cushioning valve chamber, and is pressed against itsnseat bymeans ofthe coiled spring 32.- Nhen thevalve lifts, it admitspressure fluid from the axial passage to a groove 33 and -thencethrouglithe port 34 to the cylinder in iront of the piston.

'The-operation oi the cushioning valve is ,Y vv5 its return strole, thecontrolling valve -G has a relation which is opposite to that shown 1nl3`ig. '1.V ylitt that time the pressure luid supply is connectedto theport l0, but the latter is .disconnected from the` forward end of thecylinder excepting through -the check valve 30. fis-the piston movesback the small amount of-.pressure-luid trapped in the'forward end oftheI piston-expands.' As soon vas thepressure of the cylinder fallsbelow the .supply pressure, however, the check. valve 3() lifts andpermitspassage of pressure ,iuid from the porti() -and the supply .spaceto the forward end of' the'cylinder. The' pressure-Huid will.,therefore, be 'admitted through vthegcheck valve. until the valve-6reverses thepositionxand connectsthe port l0 to the exhaust. .Thepressurefluid 4infront ofthe piston, however, being unable to .escapeis't-rapped thereat andforms a'V- high 'pressure ycushion checking theAtor- Ward movement of thepiston. The weight of the. drill steels and thefact that the pressure-fluid at the top of the pistonacts against thepiston it acts against a lesser area only, causes afjorward or downwardmovementof Athe piston 'to take place against the cushion.'

This movement, however, is quickly Ichecked by the cushion and thepiston is returned," this 'effecting the desired reciprocatory movementof the toolf The cushion thus automatically'built up willalso beautomatically maintained for as itspressure tend-sto drop by reason ofleakage orany other cause, the check valve4 will liften the backstroke'oif the piston and allowthe passage o--an additional amount ofpressure-fluid to theff'or` ward end of the cylinden LThis permits thetool to be' run'. indefinitely on the cushion 115 Without attention.Since thecushioning valve is located between the valve chamber andthe-cylinder and at substantially the exit point in the exhaust portfrom the cylinder,

the clearance space allowed thecushion is-re- '12s; duced. to a minimum.The momentthe piston stai't'son ',its'downward `rnove'nxen't it `.meetsa cylinderful. of pressure fluid at'pipe increment of advancebythe-piston. This, vtogether with the-fact that there' isv little or noclearance,'malres it impossible for the pistonto' strike the lower head.y

While I have `herein shown and described 1 30 the same'is not limited tothe details of con# lstruct-ion or Vrelative Varrangement of parts,

but that extensivedeviations may be made therefrom without depart-in gfrom the. spirit thereof.v

VClaims;

1. Inja direcbacting engn'ie,4 `the combination with 'a piston and acylinder havtworpass'age's leading to one end of fthe e'y ind'er, of auclieelevalv'e in one et said passages adapted toadmit--pressure luid to"andi'estrictthe exhaust from said end et the "cylinde'ig'and means for'cutting o said'cylinder'end fromv lthe exhaust through the 'secondpassage while opening the cylinder tothe admission'through said-I cheek`valve and the first passagei 2. In a direct-acting engine, thecombination'wlth'- a piston and a cylinder having two passages leading'to one end pf the cylinder,

alnormally inoperative inwardly opening check valve in one of saidpassages, and means for cutting ofi' said cylinder end from v theexhaust through the second passage,

V while rendering said check-valve operative. i 3. `Ina direct-actingengine the combin-ation with a piston-and cylinder of a valve foralternately admitting pressure-fluid to,

' and exhausting the same from, the .epposite ends of the piston, anormally inoperative check valve, and means for cutting oi'f acylinderend/from the exhaust while openfI through ing the' cylinder tothe admission .the-said check valve. 31

4. In-adireetacting engine, the eombina' tionA witha piston and acylinder having two passages leading to one endet the piston, of aninwardly opening check-valve, and means whereby one of. said passages.may be Closed and at the same time the,

other opened throughsaidV checlevalve.

' 5. In a directacting engine, the combination with a piston and acylinder having two ports located `at two different pointslongitudinally of the cylinder, of an inwardly opening cheek-valve forthe .port most remote from the end oi 'the cylinder, and a Amanuallyoperable valve for closing Hthe other port.

. 6. In a direct-actingengine, the combination with a pistonand yacylinder having.

two ports located-.at two dii'erent points longitudinally of thecylinder, of a normally Vinoperative check-valve for the port mest'remote from the end of the cylinder, and manually operable means forclosing the other port and rendering said cheek-Valve operative.

7. In a direct-acting' engine the combination'ywith a cylinder, of apiston, a valve, a port leading to one end of the cylinder and adaptedto be connected alternately with the admission and the exhaust throughsaidv valve, a check valve controlling coimnunicaends'of the-piston, anormally inoperative check valve adapted to a'dmit pressure fluid to andrestrict the exliaustfrom vone end of the cylinder, and manuallyoperable means for cutting oft a cylinder end from the exhaust'andsimultaneouslyrendering said check valve operative.

9..In a direct actingengine, the combination with a piston andcylinderof a valve for alternately admitting pressure fluid to, and exhaustingthe same from, the opposite ends of the piston, a check valve, and amanuallyl operable valve for cutting oil2 a cylinder end from theexhaust while 'opening the same to the admission through said checkvalve, said check valve being carried by said manually operable valve.

10. In a direct-acting engine, the combination with a piston andcylinder, of a Valve' for alternately admitting pressure iiuid to, andexhausting the saine from, the opposite ends of the piston,a manually.operable valve for cutting ott onelend oi? the cylinder from the exhaustto form a cushion for the piston when moving in one direction,

and a check valve carried by said manually ,operable valve adapted toopen said cylinbination with a piston and cylinder, of a valve foralternately admitting pressure fluid to, andexhaustmg the'same from, the

4'opposite ends of the piston, a manually operable valve provided withpassages QS and Q9, and a check valve SO permitting` the entrance ofpressure fluid through the passages 28' and 29 into the cylinder end,but cutting off the exhaust of pressure Huid from said cylinder.

12. In a directeacting engine, the combination with a piston andcylinder, of a Vcontrolling valve, a port leading from one end of thecylinder and alternately connected with the vadmission and exhaustspaces through said controlling valve, a check valve opening toward thecylinder space, and a valve provided with `passages for permitting, whenin one position, the direct admission of pressure fluid to and exhaustfrom said cylinder end through said port, and which in another psitioncuts off such direct com mnnication and establishes an indirect in-AWard communicationv between said port' and' cylinder end by Way ofsaidcheck valve. valve. v A

13. In la direct-acting engine, ,the coinbinationv with a piston and acylinder having'a' main port and a supplementary porti leading from oneend of the cylinder, of a' controlling valve for controlling theadmission and exhaust' vto and fromsaidV main port," a cushioning valveprovided with a main passage adapted normally to l1permit.

Athe admission of pressure iuid to angl exi-V liaust from the cylinderby Wayof said main port, and provided With a .supplementary passagenormally out of register With said main port, manually operable meansfor Lassie@ moving said valve into vposition to cut oi the valv'e, toadmitpressure luid'to but pr vent escape 'of fluid from the cylinder byWay of said supplementary port.

' In testimony whereof, I have signed my name to this specification, inthepresence of A two subscribing Witnesses. y GEO. H:.GLMAN.

1l/Vitnesses t THOMAS B. Boo'rni ROBERT H; KAMMLER.

